Rony
Moderator
In this work, properties of sulphate technogenic raw material – flue gas desulphurization (FGD) gypsum have been
investigated in order to obtain α-hemihydrate gypsum as gypsum binding material. FGD gypsum is produced as a by
product during the process of desulphurization of exhaust gas emitted in power stations heated by fuel containing
sulphur. It has been determined that α-hemihydrate gypsum can be obtained from FGD gypsum under hydrothermal
conditions at 125 °C and 130 °C. The compressive strength of gypsum samples is 13 MPa – 16 MPa after 2 h of
hardening and it depends on temperature and time of isothermic curing. The compressive strength of the same samples
in dry state is 49 MPa – 67 MPa. SEM analysis data showed that the properties of α-hemihydrate gypsum significantly
depend on the shape and size of its crystals: when crystals have near form to regular hexagonal – shaped prism with
length and width ratio approx. of 4 : 1, the gypsum exhibits the high quality mechanical and physical properties.
Keywords: flue gas desulphurization (FGD) gypsum α-hemihydrate gypsum, calcium sulphate dihydrate, dehydration,
hydration.
investigated in order to obtain α-hemihydrate gypsum as gypsum binding material. FGD gypsum is produced as a by
product during the process of desulphurization of exhaust gas emitted in power stations heated by fuel containing
sulphur. It has been determined that α-hemihydrate gypsum can be obtained from FGD gypsum under hydrothermal
conditions at 125 °C and 130 °C. The compressive strength of gypsum samples is 13 MPa – 16 MPa after 2 h of
hardening and it depends on temperature and time of isothermic curing. The compressive strength of the same samples
in dry state is 49 MPa – 67 MPa. SEM analysis data showed that the properties of α-hemihydrate gypsum significantly
depend on the shape and size of its crystals: when crystals have near form to regular hexagonal – shaped prism with
length and width ratio approx. of 4 : 1, the gypsum exhibits the high quality mechanical and physical properties.
Keywords: flue gas desulphurization (FGD) gypsum α-hemihydrate gypsum, calcium sulphate dihydrate, dehydration,
hydration.